U.S. patent application number 15/113299 was filed with the patent office on 2017-06-15 for plasma treatment device and wafer transfer tray.
The applicant listed for this patent is ULVAC, INC.. Invention is credited to Tsuyoshi AIHARA, Ryuichiro KAMIMURA, Naoki MORIGUCHI, Toshiyuki NAKAMURA, Yamato OSADA.
Application Number | 20170170047 15/113299 |
Document ID | / |
Family ID | 53681418 |
Filed Date | 2017-06-15 |
United States Patent
Application |
20170170047 |
Kind Code |
A1 |
NAKAMURA; Toshiyuki ; et
al. |
June 15, 2017 |
PLASMA TREATMENT DEVICE AND WAFER TRANSFER TRAY
Abstract
A plasma treatment apparatus includes a wafer transfer tray
having a first surface and a second surface opposite to the first
surface and configured to hold a wafer on the first surface, a
cooling unit configured to cool the wafer transfer tray, a
conductive supporter configured to support the second surface of
the wafer transfer tray, and a double-surface electrostatic
attractor configured to electrostatically attract the wafer to the
first surface of the wafer transfer tray and electrostatically
attract the supporter to the second surface of the wafer transfer
tray.
Inventors: |
NAKAMURA; Toshiyuki;
(Chigasaki-shi, JP) ; MORIGUCHI; Naoki;
(Chigasaki-shi, JP) ; KAMIMURA; Ryuichiro;
(Chigasaki-shi, JP) ; OSADA; Yamato;
(Chigasaki-shi, JP) ; AIHARA; Tsuyoshi;
(Chigasaki-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
ULVAC, INC. |
Chigasaki-shi |
|
JP |
|
|
Family ID: |
53681418 |
Appl. No.: |
15/113299 |
Filed: |
January 21, 2015 |
PCT Filed: |
January 21, 2015 |
PCT NO: |
PCT/JP2015/051523 |
371 Date: |
November 30, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01L 21/67103 20130101;
H01L 21/67313 20130101; H01L 21/67333 20130101; H01L 21/6831
20130101; H01L 21/67069 20130101; H01L 21/6833 20130101; H01J
37/32724 20130101; H01L 21/68771 20130101; H01L 21/67109 20130101;
H01J 37/32733 20130101; H01L 21/67098 20130101 |
International
Class: |
H01L 21/683 20060101
H01L021/683; H01L 21/67 20060101 H01L021/67; H01J 37/32 20060101
H01J037/32; H01L 21/673 20060101 H01L021/673 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 22, 2014 |
JP |
2014-009682 |
Claims
1. A plasma treatment apparatus comprising: a wafer transfer tray
having a first surface and a second surface opposite to the first
surface, and configured to hold a wafer on the first surface; a
cooling unit configured to cool the wafer transfer tray; a
conductive supporter configured to support the second surface of
the wafer transfer tray; and a double-surface electrostatic
attractor configured to electrostatically attract the wafer to the
first surface of the wafer transfer tray and electrostatically
attract the supporter to the second surface of the wafer transfer
tray.
2. The plasma treatment apparatus according to claim 1, wherein the
wafer transfer tray has a base formed of an insulating body, a
first conductive layer for electrostatic attraction embedded at a
position in the vicinity of a first surface of the base, and a
second conductive layer for electrostatic attraction embedded at a
position in the vicinity of a second surface of the base and
electrically connected to the first conductive layer, and a direct
current voltage application unit configured to apply a direct
current voltage is connected to the first conductive layer and the
second conductive layer, and a ground section is connected to the
supporter so that the supporter has a ground potential with respect
to the direct current voltage.
3. The plasma treatment apparatus according to claim 1, wherein the
wafer transfer tray has a base formed of a high resistance body
having a resistance value of 10.sup.8.OMEGA. or more and
10.sup.11.OMEGA. or less, and a first conductive layer for
electrostatic attraction embedded at a position in the vicinity of
the first surface of the base, and a direct current voltage
application unit configured to apply a direct current voltage is
connected to the first conductive layer and a ground section is
connected to the supporter so that the supporter has a ground
potential with respect to the direct current voltage.
4. The plasma treatment apparatus according to claim 1, wherein the
wafer transfer tray has a base formed of an insulating body, a
first conductive layer for electrostatic attraction embedded at a
position in the vicinity of the first surface of the base, and a
conductor disposed to be exposed to the second surface of the base,
the supporter has an insulating layer disposed on a support surface
facing to the wafer transfer tray and in which a second conductive
layer for electrostatic attraction is embedded, and a direct
current voltage application unit configured to apply a direct
current voltage is connected to the first conductive layer and the
second conductive layer.
5. The plasma treatment apparatus according to claim 1, wherein the
wafer transfer tray has a base formed of a metal, a first
insulating layer disposed at the first surface of the base and in
which a first conductive layer for electrostatic attraction is
embedded, and a second insulating layer disposed at the second
surface of the base and in which a second conductive layer for
electrostatic attraction electrically connected to the first
conductive layer is embedded, a direct current voltage application
unit configured to apply a direct current voltage is connected to
the first conductive layer and the second conductive layer, and a
ground section is connected to the supporter so that the supporter
has a ground potential with respect to the direct current
voltage.
6. The plasma treatment apparatus according to claim 1, wherein the
wafer transfer tray has a base formed of a metal, and a first
insulating layer disposed at the first surface of the base and in
which a first conductive layer for electrostatic attraction is
embedded, the supporter has a second insulating layer disposed at a
support surface facing to the wafer transfer tray and in which a
second conductive layer for electrostatic attraction is embedded,
and a direct current voltage application unit configured to apply a
direct current voltage is connected to the first conductive layer
and the second conductive layer.
7. The plasma treatment apparatus according to claim 1, wherein the
wafer transfer tray has a base formed of a metal that constitutes a
conductor for electrostatic attraction, and an insulating layer
configured to cover an outer circumferential surface of the base, a
direct current voltage application unit configured to apply a
direct current voltage is connected to the base, and a ground
section is connected to the supporter so that the supporter has a
ground potential with respect to the direct current voltage.
8. The plasma treatment apparatus according to claim 1, wherein the
wafer transfer tray has a base formed of a metal that constitutes a
conductor for electrostatic attraction, and an insulating layer
configured to cover an outer circumferential surface of the base,
the supporter has an insulating layer disposed at a support surface
facing to the wafer transfer tray and in which a second conductive
layer for electrostatic attraction is embedded, and a direct
current voltage application unit configured to apply a direct
current voltage is connected to the base.
9. The plasma treatment apparatus according to claim 2, wherein the
ground section comprises a low-pass filter configured to cut an
alternating current voltage having a predetermined frequency range
applied to the supporter.
10. (canceled)
11. The plasma treatment apparatus according to claim 3, wherein
the ground section comprises a low-pass filter configured to cut an
alternating current voltage having a predetermined frequency range
applied to the supporter.
12. The plasma treatment apparatus according to claim 5, wherein
the ground section comprises a low-pass filter configured to cut an
alternating current voltage having a predetermined frequency range
applied to the supporter.
13. The plasma treatment apparatus according to claim 7, wherein
the ground section comprises a low-pass filter configured to cut an
alternating current voltage having a predetermined frequency range
applied to the supporter.
14. A wafer transfer tray of a plasma treatment apparatus
comprising: a wafer transfer tray having a first surface and a
second surface opposite to the first surface and configured to hold
a wafer on the first surface; a cooling unit configured to cool the
wafer transfer tray; a supporter configured to support the second
surface of the wafer transfer tray and having a ground section
setting a potential of the supporter to a ground potential with
respect to a direct current voltage; and a conductor for
electrostatic attraction connected to a direct current voltage
application unit configured to apply a direct current voltage and
embedded in the base.
Description
TECHNICAL FIELD
[0001] The present invention relates to a plasma treatment
apparatus and a wafer transportation tray, and more particularly,
to fixture of a wafer transfer tray.
[0002] Priority is claimed on Japanese Patent Application No.
2014-009682, filed Jan. 22, 2014, the content of which is
incorporated herein by reference.
BACKGROUND ART
[0003] In the related art, in manufacture of a semiconductor
device, when a plurality of wafers or the like are batch-processed
through plasma treatment, the batch processing is generally
performed using a wafer transfer tray. For example, a plurality of
wafers are placed on one surface of the wafer transfer tray. The
wafer transfer tray is placed on a supporter of a plasma treatment
apparatus. The supporter acts as one electrode when the plasma
treatment is performed.
[0004] When the wafers are plasma-treated in the plasma treatment
apparatus, if the wafers are fixed to the wafer transfer tray using
a pressing means, fixation of the wafers is time-consuming and thus
an effective area in a wafer surface is reduced. For this reason,
for example, in Patent Literature 1, a plasma treatment apparatus
for fixing wafers to a wafer transfer tray using electrostatic
attraction is disclosed.
[0005] Meanwhile, when the wafers are plasma-treated in the plasma
treatment apparatus, the temperature of the wafer transfer tray is
increased by plasma. For this reason, in the above-mentioned plasma
treatment apparatus, the plasma treatment apparatus configured to
form a flow path through which a cooling gas flows between the
wafer transfer tray and a supporter that supports the wafer
transfer tray, and cool the wafer transfer tray using a cooling gas
is disclosed.
[0006] In the plasma treatment apparatus having the above-mentioned
configuration, in order to minimize leakage of the cooling gas
flowing between the wafer transfer tray and the supporter, the
wafer transfer tray and the supporter should closely contact to
each other. For this reason, a mechanical clamp configured to
mechanically attach the wafer transfer tray and the supporter is
formed.
PRIOR ART DOCUMENTS
Patent Documents
[0007] [Patent Literature 1] Re-publication of PCT International
Publication No. WO2010/095540
SUMMARY OF THE INVENTION
Problems to be Solved by the Invention
[0008] However, the above-mentioned plasma treatment apparatus has
a configuration of mechanically attaching the wafer transfer tray
and the supporter that supports the wafer transfer tray using the
mechanical clamp. For this reason, an operation when the wafer
transfer tray is fixed to the supporter becomes complicated. In
particular, structurally, since the mechanical clamp comes in
contact with a circumferential edge portion of the wafer transfer
tray to be fixed thereto, adhesion between the wafer transfer tray
and the supporter may be decreased in the vicinity of a central
portion of the wafer transfer tray.
[0009] In consideration of the above-mentioned problems, the
present invention is directed to provide a plasma treatment
apparatus and a wafer transfer tray in which the wafer transfer
tray and a supporter that supports the wafer transfer tray can be
closely contact to each other easily and uniformly across an entire
support surface.
Means for Solving the Problems
[0010] In order to solve the problems, some aspects of the present
invention have provided the following plasma treatment apparatus
and wafer transfer tray.
That is, a plasma treatment apparatus according to a first aspect
of the present invention includes a wafer transfer tray having a
first surface and a second surface opposite to the first surface,
and configured to hold a wafer on the first surface; a cooling unit
configured to cool the wafer transfer tray; a conductive supporter
configured to support the second surface of the wafer transfer
tray; and a double-surface electrostatic attractor configured to
electrostatically attract the wafer to the first surface of the
wafer transfer tray and electrostatically attract the supporter to
the second surface of the wafer transfer tray.
[0011] In the first aspect, the wafer transfer tray may have a base
formed of an insulating body, a first conductive layer for
electrostatic attraction embedded at a position in the vicinity of
a first surface of the base, and a second conductive layer for
electrostatic attraction embedded at a position in the vicinity of
a second surface of the base and electrically connected to the
first conductive layer, a direct current voltage application unit
configured to apply a direct current voltage may be connected to
the first conductive layer and the second conductive layer, and a
ground section may be connected to the supporter so that the
supporter has a ground potential with respect to the direct current
voltage.
[0012] In the first aspect, the wafer transfer tray may have a base
formed of a high resistance body having a resistance value of
10.sup.8.OMEGA. or more and 10.sup.11.OMEGA. or less, and a first
conductive layer for electrostatic attraction embedded at a
position in the vicinity of the first surface of the base, a direct
current voltage application unit configured to apply a direct
current voltage may be connected to the first conductive layer, and
a ground section may be connected to the supporter so that the
supporter has a ground potential with respect to the direct current
voltage.
[0013] In the first aspect, the wafer transfer tray may have a base
formed of an insulating body, a first conductive layer for
electrostatic attraction embedded at a position in the vicinity of
the first surface of the base, and a conductor disposed to be
exposed to the second surface of the base, the supporter may have
an insulating layer disposed on a support surface facing to the
wafer transfer tray and in which a second conductive layer for
electrostatic attraction is embedded, and a direct current voltage
application unit configured to apply a direct current voltage may
be connected to the first conductive layer and the second
conductive layer.
[0014] In the first aspect, the wafer transfer tray may have a base
formed of a metal, a first insulating layer disposed at the first
surface of the base and in which a first conductive layer for
electrostatic attraction is embedded, and a second insulating layer
disposed at the second surface of the base and in which a second
conductive layer for electrostatic attraction electrically
connected to the first conductive layer is embedded, a direct
current voltage application unit configured to apply a direct
current voltage may be connected to the first conductive layer and
the second conductive layer, and a ground section may be connected
to the supporter so that the supporter has a ground potential with
respect to the direct current voltage.
[0015] In the first aspect, the wafer transfer tray may have a base
formed of a metal, and a first insulating layer disposed at the
first surface of the base and in which a first conductive layer for
electrostatic attraction is embedded, the supporter may have a
second insulating layer disposed at a support surface facing to the
wafer transfer tray and in which a second conductive layer for
electrostatic attraction is embedded, and a direct current voltage
application unit configured to apply a direct current voltage may
be connected to the first conductive layer and the second
conductive layer.
[0016] In the first aspect, the wafer transfer tray may have a base
formed of a metal that constitutes a conductor for electrostatic
attraction, and an insulating layer configured to cover an outer
circumferential surface of the base, a direct current voltage
application unit configured to apply a direct current voltage may
be connected to the base, and a ground section may be connected to
the supporter so that the supporter has a ground potential with
respect to the direct current voltage.
[0017] In the first aspect, the wafer transfer tray may have a base
formed of a metal that constitutes a conductor for electrostatic
attraction, and an insulating layer configured to cover an outer
circumferential surface of the base, the supporter may have an
insulating layer disposed at a support surface facing to the wafer
transfer tray and in which a second conductive layer for
electrostatic attraction is embedded, and a direct current voltage
application unit configured to apply a direct current voltage may
be connected to the base.
[0018] In the first aspect, the ground section may include a
low-pass filter configured to cut an alternating current voltage
having a predetermined frequency range applied to the
supporter.
[0019] A wafer transfer tray of a plasma treatment apparatus
according to a second aspect of the present invention includes a
wafer transfer tray having a first surface and a second surface
opposite to the first surface and configured to hold a wafer on the
first surface; a cooling unit configured to cool the wafer transfer
tray; a supporter configured to support the second surface of the
wafer transfer tray and having a ground section setting a potential
of the supporter to a ground potential with respect to a direct
current voltage; and a conductor for electrostatic attraction
connected to a direct current voltage application unit configured
to apply a direct current voltage and embedded in the base.
Effects of the Invention
[0020] According to the plasma treatment apparatus and the wafer
transfer tray according to the above-mentioned aspects of the
present invention, the wafer and the supporter are
electrostatically attracted by the double-surface electrostatic
attractor of the plasma treatment apparatus at both of the first
surface and the second surface of the wafer transfer tray.
[0021] Accordingly, when the plasma is generated between the
supporter that forms the lower electrode and the upper electrode
and plasma treatment is performed on the wafer, the wafer transfer
tray can be efficiently and uniformly cooled. For this reason, the
plasma treatment can be performed on the wafer uniformly and
accurately.
[0022] In addition, the wafer transfer tray and the supporter
closely contact with each other by electrostatically attracting the
supporter to the wafer transfer tray. For this reason, the wafer
transfer tray can be efficiently cooled by the cooling gas supplied
from the gas supply unit. In addition, loss of the cooling gas due
to dissipation can also be reduced by close contact between the
wafer transfer tray and the supporter.
[0023] Then, for example, in comparison with the configuration in
which the wafer transfer tray and the supporter are fixed by the
mechanical clamp as in the related art, since the plasma treatment
apparatus according to the present invention electrically attracts
the wafer transfer tray and the supporter, a mechanical movable
portion is reduced. Accordingly, the wafer transfer tray and the
supporter can be easily fixed by a simple configuration.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] FIG. 1 is a cross-sectional view showing a plasma treatment
apparatus according to a first embodiment of the present invention
as a whole.
[0025] FIG. 2 is a plan view of a wafer transfer tray according to
the first embodiment of the present invention viewed from
above.
[0026] FIG. 3 is a cross-sectional view showing a support section
of a plasma treatment apparatus of a second embodiment of the
present invention.
[0027] FIG. 4 is a cross-sectional view showing a support section
of a plasma treatment apparatus of a third embodiment of the
present invention.
[0028] FIG. 5 is a cross-sectional view showing a support section
of a plasma treatment apparatus of a fourth embodiment of the
present invention.
[0029] FIG. 6 is a cross-sectional view showing a support section
of a plasma treatment apparatus of a fifth embodiment of the
present invention.
[0030] FIG. 7 is a cross-sectional view showing a support section
of a plasma treatment apparatus of a sixth embodiment of the
present invention.
[0031] FIG. 8 is a cross-sectional view showing a support section
of a plasma treatment apparatus of a seventh embodiment of the
present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0032] Hereinafter, embodiments of a plasma treatment apparatus and
a wafer transfer tray according to the present invention will be
described with reference to the accompanying drawings. Further, the
embodiments are provided to specifically describe the present
invention such that the spirit of the present invention can be
better understood, but are not intended to limit the present
invention unless the context clearly indicates otherwise. In
addition, in the drawings used in the following description, some
parts may be exaggerated for clarity in order to clearly describe
the present invention, and dimensions, ratios, and so on, of
components are not limited to being the same as in reality.
First Embodiment
[0033] FIG. 1 is a cross-sectional view showing a plasma treatment
apparatus according to a first embodiment of the present invention
as a whole.
A plasma treatment apparatus 10 includes a plasma treatment tank
(chamber) 11, an upper electrode 18 disposed in the vicinity of an
upper surface in the plasma treatment tank 11, a supporter 12
disposed in the vicinity of a bottom surface in the plasma
treatment tank 11 and configured to form a lower electrode, and a
support section 15 having a wafer transfer tray 13 placed on the
supporter 12.
[0034] The wafer transfer tray 13 has a substantially disk-shaped
base 21, and a first conductive layer 22 for electrostatic
attraction embedded at a position closer to one surface (a first
surface) 21a than the other surface (a second surface) 21b of the
base 21. In addition, a concave section 23 into which a wafer W
serving as a substance to be treated is inserted is formed in the
one surface 21a of the base 21.
[0035] The base 21 is constituted by a high resistance body having
a resistance value of 10.sup.8.OMEGA. or more and 10.sup.11.OMEGA.
or less.
[0036] The high resistance body may be, for example, a ceramic
plate, a resistance value of which is controlled.
[0037] In addition, the first conductive layer 22 is formed of a
metal such as aluminum, tungsten or titanium, or an alloy including
these metals. The first conductive layer 22 may be formed to be
spread parallel to the one surface 21a of the base 21, for example,
at a depth position of hundreds of micrometers to several
millimeters from the one surface 21a of the base 21.
[0038] The above-mentioned wafer transfer tray 13 may be obtained
by, for example, spraying a metal that constitutes the first
conductive layer 22 onto a ceramic plate.
[0039] FIG. 2 is a plan view showing the wafer transfer tray 13
from an upper side. The wafer transfer tray 13 has a plurality of
concave sections 23, 23 on which a plurality of wafers W having
diameters of, for example, about 2 to 4 inches can be disposed. In
the embodiment, four concave sections 23 are formed such that four
wafers W can be placed thereon. Further, in order to efficiently
perform plasma treatment of the wafers W, for example, about 5 to
30 concave sections 23 may be formed in the one surface 21a of the
base 21.
[0040] Referring to FIG. 1 again, a gas supply unit 25 configured
to supply a cooling gas and serving as a cooling unit configured to
cool the wafer transfer tray 13 is connected to the support section
15. The cooling gas supplied from the gas supply unit 25 flows
along, for example, a gas flow path (not shown) formed at one
surface (a first surface) 13a side of the wafer transfer tray 13 to
cool the wafer transfer tray 13.
Further, when a structure in which a flow path is formed in the
base 21 and a coolant flows through the flow path to cool the wafer
transfer tray 13 is provided, cooling efficiency of the wafers can
be further improved.
[0041] The cooling gas supplied from the gas supply unit 25 should
be a gas that does not cause a chemical reaction with a plasma
atmosphere P in the plasma treatment tank 11 and a laminated film
or the like of the wafer W, and may be an inert gas. Further, in
order to be used for control of a temperature increase, the inert
gas may be helium gas having a low boiling point and a function as
a coolant.
[0042] A direct current voltage application unit 26 configured to
apply a direct current voltage is connected to the first conductive
layer 22.
[0043] The direct current voltage application unit 26 is
constituted by, for example, a direct current power supply
apparatus, a connecting wiring, or the like. A direct current
voltage applied to the first conductive layer 22 may be, for
example, about 1000 V to 5000 V. The first conductive layer 22 is
positively or negatively charged by applying direct current
voltage.
[0044] The supporter 12 has a flat shape at least in a support
surface 12a that comes in contact with the other surface (a second
surface) 13b of the wafer transfer tray 13 to support the other
surface, and supports the wafer transfer tray 13 at the support
surface 12a. The entire supporter 12 is constituted by a conductor
such as a metal or the like, for example, aluminum, titanium or
iron, or an alloy including these metals.
[0045] A radio frequency voltage application unit 27 configured to
apply a radio frequency voltage is connected to the supporter
12.
[0046] The radio frequency voltage application unit 27 is
constituted by, for example, a radio frequency power supply
apparatus, a connecting wiring, or the like. Accordingly, the
supporter 12 functions as a lower electrode configured to generate
the plasma P between the upper electrode 18 and the supporter
12.
[0047] In addition, a ground section 28 is connected to the
supporter 12 so that the supporter 12 has a ground potential with
respect to the direct current voltage. The ground section 28 is
constituted by, for example, a low-pass filter, a grounding wiring,
or the like. Among these, the low-pass filter cuts the radio
frequency voltage applied by the radio frequency voltage
application unit 27 and connects the supporter 12 to the grounding
wiring with respect to only the direct current voltage.
Accordingly, the supporter 12 has a ground potential with respect
to the direct current voltage, and the radio frequency voltage
applied by the radio frequency voltage application unit 27 flows to
the ground section 28 and is not lost.
[0048] In the embodiment having the above-mentioned configuration,
a double-surface electrostatic attractor is constituted by the base
21, the first conductive layer 22, the supporter 12, the direct
current voltage application unit 26 and the ground section 28.
[0049] Actions of the plasma treatment apparatus and the wafer
transfer tray having the above-mentioned configurations will be
described.
[0050] In the plasma treatment apparatus 10 according to the
embodiment, the first conductive layer 22 of the wafer transfer
tray 13 is positively or negatively charged by applying the direct
current voltage to the first conductive layer 22 using the direct
current voltage application unit 26. Accordingly, the wafer W is
electrostatically attracted to the wafer transfer tray 13 by a
Coulomb's force (an electrostatic attractive force) generated by an
electric charge induced between the wafer W placed on the concave
section 23 of the wafer transfer tray 13 and the first conductive
layer 22.
[0051] Meanwhile, the potential of the support body 12 becomes a
ground potential with respect to the direct current voltage by the
ground section 28. Then, since the base 21 that forms the wafer
transfer tray 13 is constituted by a high resistance body having a
resistance value of 10.sup.8.OMEGA. or more and 10.sup.11.OMEGA. or
less, conductivity is slightly applied to the base 21 and the wafer
transfer tray 13 is electrostatically attracted to the supporter 12
by a Johnson-Labeque's force (an electrostatic attractive force)
generated by electric charge movement in the base 21.
[0052] In this way, the wafer W and the supporter 12 are
electrostatically attracted to both of the one surface 13a and the
other surface 13b of the wafer transfer tray 13 by the
double-surface electrostatic attractor of the plasma treatment
apparatus 10, respectively. That is, the wafer W is
electrostatically attracted to the one surface 13a of the wafer
transfer tray 13 and the supporter 12 is electrostatically
attracted to the other surface 13b of the wafer transfer tray
13.
[0053] Accordingly, when the plasma P is generated between the
supporter 12 that forms the lower electrode and the upper electrode
18 and plasma treatment is performed on the wafer W, the wafer
transfer tray can be efficiently and uniformly cooled, and the
plasma treatment can be performed on the wafer W uniformly and
accurately.
[0054] In addition, as the supporter 12 is electrostatically
attracted to the wafer transfer tray 13, the wafer transfer tray 13
closely contacts with the supporter 12. For this reason, the wafer
transfer tray 13 can be efficiently cooled by a cooling gas
supplied from the gas supply unit 25. In addition, a loss of the
cooling gas due to dissipation can be reduced by close contact
between the wafer transfer tray 13 and the supporter 12.
[0055] Then, for example, in comparison with the configuration in
which the wafer transfer tray and the supporter are fixed by the
mechanical clamp as in the related art, since the plasma treatment
apparatus 10 of the present invention electrically attracts the
wafer transfer tray and the supporter, a mechanical movable portion
is reduced. Accordingly, the wafer transfer tray and the supporter
can be easily fixed by a simple configuration.
[0056] Further, in the above-mentioned embodiment, while the first
conductive layer 22 is shown as an example of a monopole type, a
bipolar type in which a plurality of conductive layers have
different polarities may be provided.
[0057] Hereinafter, another embodiment of the plasma treatment
apparatus of the present invention will be described. In the
following embodiments, only configurations and actions of portions
related to the wafer transfer tray and the supporter will be
described. The other configurations are the same as the
above-mentioned first embodiment. In addition, the same members as
the above-mentioned first embodiment are designated by the same
reference numerals, and a detailed description of the
configurations will be omitted.
Second Embodiment
[0058] FIG. 3 is a cross-sectional view showing the vicinity of a
support section of a plasma treatment apparatus according to a
second embodiment of the present invention. A wafer transfer tray
32 in a support section 31 of a plasma treatment apparatus 30
according to the second embodiment has a base 33 formed of an
insulating body, a first conductive layer 34 for electrostatic
attraction embedded at a position closer to one surface (a first
surface) 33a than the other surface 33b of the base 33, and a
second conductive layer 35 for electrostatic attraction embedded at
a position closer to the other surface (a second surface) 33b than
the one surface 33a of the base 33.
[0059] The base 33 is constituted by, a for example, a ceramic
plate or the like. The first conductive layer 34 and the second
conductive layer 35 are electrically connected by a conductor
extending in a thickness direction of the wafer transfer tray
32.
[0060] The first conductive layer 34 and the second conductive
layer 35 are formed of a metal, such as, for example, aluminum,
tungsten or titanium, or an alloy including these metals. The first
conductive layer 34 may be formed to spread parallel to the one
surface 33a of the base 33 at, for example, a depth position of
hundreds of micrometers from the one surface 33a of the base 33. In
addition, the second conductive layer 35 may be formed to spread
parallel to the other surface 33b of the base 33 at, for example, a
depth position of hundreds of micrometers from the other surface
33b of the base 33.
[0061] The above-mentioned wafer transfer tray 32 can be obtained
by, for example, spraying a metal that constitutes the first
conductive layer 34 and the second conductive layer 35 onto the
ceramic plate.
[0062] The gas supply unit 25 configured to supply a cooling gas
and serving as a cooling unit configured to cool the wafer transfer
tray 32 is connected to the support section 31. The cooling gas
supplied from the gas supply unit 25 flows along a gas flow path
(not shown) formed at, for example, one surface (a first surface)
33a side of the wafer transfer tray 32 to cool the wafer transfer
tray 32.
[0063] A direct current voltage application unit 36 configured to
apply a direct current voltage is connected to the first conductive
layer 34 and the second conductive layer 35. The direct current
voltage application unit 36 is constituted by, for example, a
direct current power supply apparatus, a connecting wiring, or the
like. The first conductive layer 34 and the second conductive layer
35 are positively or negatively charged by application of the
above-mentioned direct current voltage.
[0064] A supporter 37 has a flat shape at least in a support
surface 37a that comes in contact with the other surface (a second
surface) 33b of the wafer transfer tray 32 and supports the other
surface 33b, and supports the wafer transfer tray 32 at the support
surface 37a. The entire supporter 37 is constituted by a conductor
such as a metal or the like, such as, for example, aluminum,
titanium or iron, or an alloy including these metals.
[0065] A radio frequency voltage application unit 38 configured to
apply a radio frequency voltage is connected to the supporter
37.
[0066] The radio frequency voltage application unit 38 is
constituted by, for example, a radio frequency power supply
apparatus, a connecting wiring, or the like. Accordingly, the
supporter 37 functions as a lower electrode configured to generate
the plasma P between the upper electrode 18 (see FIG. 1) and the
supporter 37.
[0067] In addition, a ground section 39 is connected to the
supporter 37 so that the supporter 37 has a ground potential with
respect to the direct current voltage. The ground section 39 is
constituted by, for example, a low-pass filter, a grounding wiring,
or the like. Among these, the low-pass filter cuts the radio
frequency voltage applied by the radio frequency voltage
application unit 38 and connects the supporter 37 to the grounding
wiring with respect to only the direct current voltage.
Accordingly, the supporter 37 has a ground potential with respect
to the direct current voltage, and the radio frequency voltage
applied by the radio frequency voltage application unit 38 flows to
the ground section 39 and is not lost.
[0068] In the embodiment having the above-mentioned configuration,
a double-surface electrostatic attractor is constituted by the base
33, the first conductive layer 34, the second conductive layer 35,
the supporter 37, the direct current voltage application unit 36
and the ground section 39.
[0069] Actions of the plasma treatment apparatus and the wafer
transfer tray according to the second embodiment having the
above-mentioned configuration will be described.
[0070] In the plasma treatment apparatus 30 according to the
embodiment, as the direct current voltage is applied to the first
conductive layer 34 by the direct current voltage application unit
36, the first conductive layer 34 of the wafer transfer tray 32 is
positively or negatively charged. Accordingly, the wafer W is
electrostatically attracted to the wafer transfer tray 32 by a
Coulomb's force (an electrostatic attractive force) generated by
electric charges induced between the wafer W placed on the wafer
transfer tray 32 and the first conductive layer 34.
[0071] Meanwhile, the potential of the support body 37 becomes a
ground potential with respect to the direct current voltage by the
ground section 39. Then, as the direct current voltage is applied
to the second conductive layer 35 by the direct current voltage
application unit 36, the second conductive layer 35 of the wafer
transfer tray 32 is positively or negatively charged. Accordingly,
the supporter 37 is electrostatically attracted to the wafer
transfer tray 32 by a Coulomb's force (an electrostatic attractive
force) generated by electric charges induced between the support
surface 37a of the supporter 37 and the second conductive layer
35.
[0072] In this way, the wafer W and the supporter 37 are
electrostatically attracted by the double-surface electrostatic
attractor of the plasma treatment apparatus 30 at both of the one
surface 33a and the other surface 33b of the wafer transfer tray
32, respectively. That is, the wafer W is electrostatically
attracted to the one surface 33a of the wafer transfer tray 32 and
the supporter 37 is electrostatically attracted to the second
surface 33b of the wafer transfer tray 32.
[0073] Accordingly, when the plasma P is generated between the
supporter 37 that forms the lower electrode and the upper electrode
18 (see FIG. 1) and plasma treatment is performed on the wafer W,
the wafer transfer tray can be efficiently and uniformly cooled and
the plasma treatment can be performed on the wafer W uniformly and
accurately.
[0074] In addition, the wafer transfer tray 32 and the supporter 37
closely contact with each other by electrostatically attracting the
supporter 37 to the wafer transfer tray 32. For this reason, the
wafer transfer tray 32 can be efficiently cooled by the cooling gas
supplied from the gas supply unit 25. In addition, loss of the
cooling gas due to dissipation can be reduced by close contact of
the wafer transfer tray 32 and the supporter 37.
[0075] Then, for example, in comparison with the configuration in
which the wafer transfer tray and the supporter are fixed by the
mechanical clamp as in the related art, since the plasma treatment
apparatus 30 according to the embodiment can electrically attract
the wafer transfer tray and the supporter, a mechanical movable
portion is reduced. Accordingly, the wafer transfer tray and the
supporter can be easily fixed by a simple configuration.
Third Embodiment
[0076] FIG. 4 is a cross-sectional view showing the vicinity of a
support section of a plasma treatment apparatus according to a
third embodiment of the present invention.
A wafer transfer tray 42 in a support section 41 of a plasma
treatment apparatus 40 according to the third embodiment has a base
43 formed of an insulating body, a first conductive layer 44 for
electrostatic attraction embedded at a position closer to one
surface (a first surface) 43a than the other surface 43b of the
base 43, and a conductor 45 disposed to be exposed at the other
surface (a second surface) 43b of the base 43.
[0077] The base 43 is constituted by, for example, a ceramic plate
or the like. The first conductive layer 44 and the conductor 45 are
formed of a metal, for example, aluminum, tungsten or titanium, or
an alloy including these metals. The first conductive layer 44 may
be formed to spread parallel to the one surface 43a of the base 43
at, for example, a depth position of several millimeters from the
one surface 43a of the base 43.
[0078] The above-mentioned wafer transfer tray 42 can be obtained
by, for example, spraying the metal that constitutes the first
conductive layer 44 onto the ceramic plate.
[0079] The gas supply unit 25 configured to supply a cooling gas
and serving as a cooling unit configured to cool the wafer transfer
tray 42 is connected to the support section 41. The cooling gas
supplied from the gas supply unit 25 flows along, for example, a
gas flow path (not shown) formed at one surface (a first surface)
42a side of the wafer transfer tray 42 to cool the wafer transfer
tray 42.
[0080] A direct current voltage application unit 46a configured to
apply a direct current voltage is connected to the first conductive
layer 44. The direct current voltage application unit 46a is
constituted by, for example, a direct current power supply
apparatus, a connecting wiring, or the like. The first conductive
layer 44 is positively or negatively charged by applying direct
current voltage.
[0081] An insulating layer 47b in which second conductive layers
49a and 49b for electrostatic attraction are embedded are formed at
a support surface 47a of a supporter 47 that comes in contact with
the other surface (a second surface) 42b of the wafer transfer tray
42 to support the wafer transfer tray 42. The entire second
conductive layers 49a and 49b are constituted by a conductor of a
metal or the like, for example, aluminum, titanium or iron, or an
alloy including these metals. In addition, the insulating layer 47b
is formed of, for example, a ceramic.
[0082] A direct current voltage application unit 46b and a direct
current voltage application unit 46c configured to apply a direct
current voltage are connected to the second conductive layer 49a
and the second conductive layer 49b, respectively. The direct
current voltage application units 46b and 46c are constituted by,
for example, a direct current power supply apparatus, a connecting
wiring, or the like. The second conductive layers 49a and 49b are
charged to polarities that are opposite to each other, and form a
bipolar type electrostatic attractor.
[0083] A radio frequency voltage application unit 48 configured to
apply a radio frequency voltage is connected to the supporter
47.
The radio frequency voltage application unit 48 is constituted by,
for example, a radio frequency power supply apparatus, a connecting
wiring, or the like. Accordingly, the supporter 47 functions as a
lower electrode configured to generate the plasma P between the
upper electrode 18 (see FIG. 1) and the supporter 47.
[0084] In the embodiment having the above-mentioned configuration,
a double-surface electrostatic attractor is constituted by the base
43, the first conductive layer 44, the conductor 45, the second
conductive layers 49a and 49b, and the direct current voltage
application units 46a, 46b and 46c.
[0085] Actions of the plasma treatment apparatus and the wafer
transfer tray according to the third embodiment having the
above-mentioned configuration will be described. In the plasma
treatment apparatus 40 according to the embodiment, as the direct
current voltage is applied to the first conductive layer 44 by the
direct current voltage application unit 46a, the first conductive
layer 44 of the wafer transfer tray 42 is positively or negatively
charged. Accordingly, the wafer W is electrostatically attracted to
the wafer transfer tray 42 by a Coulomb's force (an electrostatic
attractive force) generated by electric charges induced between the
wafer W placed on the wafer transfer tray 42 and the first
conductive layer 44.
[0086] Meanwhile, direct current voltages having opposite
polarities are applied from the direct current voltage application
units 46b and 46c to the second conductive layers 49a and 49b
embedded in the insulating layer 47b formed on the supporter 47.
Accordingly, the supporter 47 is electrostatically attracted to the
wafer transfer tray 42 by a Coulomb's force (an electrostatic
attractive force) generated by electric charges induced between the
conductor 45 formed on the other surface 42b of the wafer transfer
tray 42 and the second conductive layers 49a and 49b.
[0087] In this way, the wafer W and the supporter 47 are
electrostatically attracted by the double-surface electrostatic
attractor of the plasma treatment apparatus 40 at both of the one
surface 42a and the other surface 42b of the wafer transfer tray
42, respectively. That is, the wafer W is electrostatically
attracted to the one surface 42a of the wafer transfer tray 42 and
the supporter 47 is electrostatically attracted to the other
surface 42b of the wafer transfer tray 42.
[0088] Accordingly, when the plasma P is generated between the
supporter 47 that forms a lower electrode and the upper electrode
18 (see FIG. 1) and plasma treatment is performed on the wafer W,
the wafer transfer tray can be efficiently and uniformly cooled and
the plasma treatment can be performed on the wafer W uniformly and
accurately.
[0089] In addition, the wafer transfer tray 42 and the supporter 47
closely contact with each other by electrostatically attracting the
supporter 47 to the wafer transfer tray 42. For this reason, the
wafer transfer tray 42 can be efficiently cooled by the cooling gas
supplied from the gas supply unit 25. In addition, loss of the
cooling gas due to dissipation can be reduced by close contact
between the wafer transfer tray 42 and the supporter 47.
[0090] Then, for example, in comparison with the case in which the
wafer transfer tray and the supporter are fixed by the mechanical
clamp as in the related art, since the plasma treatment apparatus
40 according to the embodiment electrically attracts the wafer
transfer tray and the supporter, a mechanical movable portion is
reduced. Accordingly, the wafer transfer tray and the supporter can
be easily fixed by a simple configuration.
Fourth Embodiment
[0091] FIG. 5 is a cross-sectional view showing the vicinity of a
support section of a plasma treatment apparatus according to a
fourth embodiment of the present invention. A wafer transfer tray
52 in a support section 51 of a plasma treatment apparatus 50 of
the fourth embodiment has a base 53 formed of a metal, a first
insulating layer 55a formed on one surface (a first surface) 53a of
the base 53 and in which a first conductive layer 54a is embedded,
and a second insulating layer 55b formed on the other surface (a
second surface) 53b of the base 53 and in which a second conductive
layer 54b is embedded.
[0092] The base 53 is formed of a metal, for example, aluminum,
titanium or iron, or an alloy including these metals. The first
conductive layer 54a and the second conductive layer 54b are
electrically connected by a conductor extending in a thickness
direction of the wafer transfer tray 52. In addition, the conductor
configured to electrically connect the first conductive layer 54a
and the second conductive layer 54b is also coated with an
insulating body to be insulated from the base 53. The first
conductive layer 54a and the second conductive layer 54b are formed
of a metal such as aluminum, tungsten or titanium, or an alloy
including these metals. The first insulating layer 55a and the
second insulating layer 55b are formed of, for example, a
ceramic.
[0093] The gas supply unit 25 configured to supply a cooling gas
and serving as a cooling unit configured to cool the wafer transfer
tray 52 is connected to the support section 51. The cooling gas
supplied from the gas supply unit 25 flows along, for example, a
gas flow path (not shown) formed at one surface (a first surface)
52a side of the wafer transfer tray 52 to cool the wafer transfer
tray 52.
[0094] A direct current voltage application unit 56 configured to
apply a direct current voltage is connected to the first conductive
layer 54a and the second conductive layer 54b. The direct current
voltage application unit 56 is constituted by, for example, a
direct current power supply apparatus, a connecting wiring, or the
like. The first conductive layer 54a and the second conductive
layer 54b are positively or negatively charged by application of
the above-mentioned direct current voltage.
[0095] A supporter 57 has a flat shape in a support surface 57a
configured to come in contact with at least the other surface (a
second surface) 52b of the wafer transfer tray 52 to support the
wafer transfer tray 52, and supports the wafer transfer tray 52 at
the support surface 57a. The entire supporter 57 is constituted by
a conductor formed of a metal or the like, for example, aluminum,
titanium or iron, or an alloy including these metals.
[0096] A radio frequency voltage application unit 58 configured to
apply a radio frequency voltage is connected to the supporter
57.
[0097] The radio frequency voltage application unit 58 is
constituted by, for example, a radio frequency power supply
apparatus, a connecting wiring, or the like. Accordingly, the
supporter 57 functions as a lower electrode configured to generate
the plasma P between the upper electrode 18 (see FIG. 1) and the
supporter 57.
[0098] In addition, a ground section 59 is connected to the
supporter 57 so that the supporter 57 has a ground potential with
respect to the direct current voltage. The ground section 59 is
constituted by, for example, a low-pass filter, a grounding wiring,
or the like. Among these, the low-pass filter cuts a radio
frequency voltage applied by the radio frequency voltage
application unit 58, and connects the supporter 57 to the grounding
wiring with respect to only the direct current voltage.
Accordingly, the supporter 57 has a ground potential with respect
to the direct current voltage, and a radio frequency voltage
applied by the radio frequency voltage application unit 58 flows to
the ground section 59 and is not lost.
[0099] In the embodiment having the above-mentioned configuration,
a double-surface electrostatic attractor is constituted by the
first insulating layer 55a in which the first conductive layer 54a
is embedded, the second insulating layer 55b in which the second
conductive layer 54b is embedded, the supporter 57, the direct
current voltage application unit 56 and the ground section 59.
[0100] Actions of the plasma treatment apparatus and the wafer
transfer tray according to the fourth embodiment having the
above-mentioned configuration will be described. In the plasma
treatment apparatus 50 according to the embodiment, as the direct
current voltage is applied to the first conductive layer 54a by the
direct current voltage application unit 56, the first conductive
layer 54a of the wafer transfer tray 52 is positively or negatively
charged. Accordingly, the wafer W is electrostatically attracted to
the wafer transfer tray 52 by a Coulomb's force (an electrostatic
attractive force) generated by electric charges induced between the
wafer W placed on the wafer transfer tray 52 and the first
conductive layer 54a.
[0101] Meanwhile, the potential of the support body 57 becomes a
ground potential with respect to the direct current voltage by the
ground section 59. Then, as the direct current voltage is applied
to the second conductive layer 54b by the direct current voltage
application unit 56, the second conductive layer 54b of the wafer
transfer tray 52 is positively or negatively charged. Accordingly,
the supporter 57 is electrostatically attracted to the wafer
transfer tray 52 by a Coulomb's force (an electrostatic attractive
force) generated by electric charges induced between the support
surface 57a of the supporter 57 and the second conductive layer
54b.
[0102] In this way, the wafer W and the supporter 57 are
electrostatically attracted by the double-surface electrostatic
attractor of the plasma treatment apparatus 50 at both of the one
surface 52a and the other surface 52b of the wafer transfer tray
52, respectively. That is, the wafer W is electrostatically
attracted to the one surface 52a of the wafer transfer tray 52 and
the supporter 57 is electrostatically attracted to the other
surface 52b of the wafer transfer tray 52.
[0103] Accordingly, when the plasma P is generated between the
supporter 57 that forms the lower electrode and the upper electrode
18 (see FIG. 1) and plasma treatment is performed on the wafer W,
the wafer transfer tray can be efficiently and uniformly cooled and
the plasma treatment can be performed on the wafer W uniformly and
accurately.
[0104] In addition, since the wafer transfer tray 52 and the
supporter 57 closely contact with each other by electrostatically
attracting the supporter 57 to the wafer transfer tray 52, the
wafer transfer tray 52 can be efficiently cooled by the cooling gas
supplied from the gas supply unit 25. In addition, loss of the
cooling gas due to dissipation can be reduced by close contact
between the wafer transfer tray 52 and the supporter 57.
[0105] Then, for example, in comparison with the configuration in
which the wafer transfer tray and the supporter are fixed by the
mechanical clamp as in the related art, since the plasma treatment
apparatus 50 according to the embodiment electrically attracts the
wafer transfer tray and the supporter, a mechanical movable portion
is reduced. Accordingly, the wafer transfer tray and the supporter
can be easily fixed by a simple configuration.
Fifth Embodiment
[0106] FIG. 6 is a cross-sectional view showing the vicinity of a
support section of a plasma treatment apparatus according to a
fifth embodiment of the present invention.
A wafer transfer tray 62 in a support section 61 of a plasma
treatment apparatus 60 according to the fifth embodiment has a base
63 formed of a metal, and a first insulating layer 69a formed on
one surface (a first surface) 63a of the base 63 and in which a
first conductive layer 64 is embedded.
[0107] The base 63 is formed of a metal such as aluminum, titanium
or iron, or an alloy including these metals. The first conductive
layer 64 is formed of a metal such as aluminum, tungsten or
titanium, or an alloy including these metals. The first insulating
layer 69a is formed of, for example, a ceramic.
[0108] The gas supply unit 25 configured to supply a cooling gas
and serving as a cooling unit configured to cool the wafer transfer
tray 62 is connected to the support section 61. The cooling gas
supplied from the gas supply unit 25 flows to, for example, a gas
flow path (not shown) formed at one surface (a first surface) 62a
side of the wafer transfer tray 62 to cool the wafer transfer tray
62.
[0109] A direct current voltage application unit 66a configured to
apply a direct current voltage is connected to the first conductive
layer 64. The direct current voltage application unit 66a is
constituted by, for example, a direct current power supply
apparatus, a connecting wiring, or the like. The first conductive
layer 64 is positively or negatively charged by application of the
above-mentioned direct current voltage.
[0110] A second insulating layer 69b in which second conductive
layers 65a and 65b for electrostatic attraction are embedded is
formed on a support surface 67a of a supporter 67 configured to
come in contact with the other surface (a second surface) 62b of
the wafer transfer tray 62 to support the wafer transfer tray
62.
The entire second conductive layers 65a and 65b are constituted by
a conductor of a metal or the like, for example, aluminum, tungsten
or titanium, or an alloy including these metals. In addition, the
second insulating layer 69b is constituted by, for example, a
ceramic.
[0111] A direct current voltage application unit 66b and a direct
current voltage application unit 66c configured to apply a direct
current voltage are connected to the second conductive layer 65a
and the second conductive layer 65b, respectively. The direct
current voltage application units 66b and 66c are constituted by,
for example, a direct current power supply apparatus and a
connecting wiring, or the like. The second conductive layers 65a
and 65b are charged with polarities that are opposite to each
other, and form a bipolar type electrostatic attractor.
[0112] A radio frequency voltage application unit 68 configured to
apply a radio frequency voltage is connected to the supporter
67.
The radio frequency voltage application unit 68 is constituted by,
for example, a radio frequency power supply apparatus, a connecting
wiring, or the like. Accordingly, the supporter 67 functions as a
lower electrode configured to generate the plasma P between the
upper electrode 18 (see FIG. 1) and the supporter 67.
[0113] In the embodiment having the above-mentioned configuration,
a double-surface electrostatic attractor is constituted by the
first insulating layer 69a in which the first conductive layer 64
is embedded, the second insulating layer 69b in which the second
conductive layers 65a and 65b are embedded, the supporter 67, and
the direct current voltage application units 66a, 66b and 66c.
[0114] Actions of the plasma treatment apparatus and wafer transfer
tray according to the fifth embodiment having the above-mentioned
configuration will be described.
In the plasma treatment apparatus 60 according to the embodiment,
as the direct current voltage is applied to the first conductive
layer 64 by the direct current voltage application unit 66a, the
first conductive layer 64 of the wafer transfer tray 62 is
positively or negatively charged. Accordingly, the wafer W is
electrostatically attracted to the wafer transfer tray 62 by a
Coulomb's force (an electrostatic attractive force) generated by
electric charges induced between the wafer W placed on the wafer
transfer tray 62 and the first conductive layer 64.
[0115] Meanwhile, as direct current voltages having polarities that
are opposite to each other are applied from the direct current
voltage application units 66b and 66c with respect to the second
conductive layers 65a and 65b embedded in the second insulating
layer 69b formed on the supporter 67, the supporter 67 is
electrostatically attracted to the wafer transfer tray 62.
[0116] In this way, the wafer W and the supporter 67 are
electrostatically attracted by the double-surface electrostatic
attractor of the plasma treatment apparatus 60 at both of one
surface 62a and the other surface 62b of the wafer transfer tray
62, respectively. That is, the wafer W is electrostatically
attracted to the one surface 62a of the wafer transfer tray 62 and
the supporter 67 is electrostatically attracted to the other
surface 62b of the wafer transfer tray 62.
[0117] Accordingly, when the plasma P is generated between the
supporter 67 that forms the lower electrode and the upper electrode
18 (see FIG. 1) and plasma treatment is performed on the wafer W,
since the wafer transfer tray can be efficiently and uniformly
cooled, the plasma treatment can be performed on the wafer W
uniformly and accurately.
[0118] In addition, the wafer transfer tray 62 and the supporter 67
closely contact with each other by electrostatically attracting the
supporter 67 to the wafer transfer tray 62. For this reason, the
wafer transfer tray 62 can be efficiently cooled by the cooling gas
supplied from the gas supply unit 25. In addition, loss of the
cooling gas due to dissipation can be reduced by close contact
between the wafer transfer tray 62 and the supporter 67.
[0119] Then, for example, in comparison with the configuration in
which the wafer transfer tray and the supporter are fixed by the
mechanical clamp as in the related art, since the plasma treatment
apparatus 60 according to the embodiment electrically attracts the
supporter to the wafer transfer tray, a mechanical movable portion
is reduced. Accordingly, the wafer transfer tray and the supporter
can be easily fixed by a simple configuration.
Sixth Embodiment
[0120] FIG. 7 is a cross-sectional view showing the vicinity of a
support section of a plasma treatment apparatus according to a
sixth embodiment of the present invention.
A wafer transfer tray 72 in a support section 71 of a plasma
treatment apparatus 70 of the sixth embodiment has a base 73 formed
of a metal, and an insulating layer 74 configured to cover an outer
circumferential surface of the base 73.
[0121] The base 73 is formed of a metal such as aluminum, titanium
or iron, or an alloy including these metals. The insulating layer
74 is formed of, for example, a ceramic.
[0122] The gas supply unit 25 configured to supply a cooling gas
and serving as a cooling unit configured to cool the wafer transfer
tray 72 is connected to the support section 71. The cooling gas
supplied from the gas supply unit 25 flows to, for example, a gas
flow path (not shown) formed at a first surface (a first surface)
72a side of the wafer transfer tray 72 to cool the wafer transfer
tray 72.
[0123] A direct current voltage application unit 76 configured to
apply a direct current voltage is connected to the base 73 formed
of a metal. The direct current voltage application unit 76 is
constituted by, for example, a direct current power supply
apparatus, a connecting wiring, or the like.
[0124] The base 73 is positively or negatively charged by
application of the above-mentioned direct current voltage.
[0125] A supporter 77 has a flat shape in a support surface 77a
configured to come in contact with at least the other surface (a
second surface) 72b of the wafer transfer tray 72 to support the
wafer transfer tray 72, and supports the wafer transfer tray 72 at
the support surface 77a. The entire supporter 77 is constituted by
a conductor of a metal or the like, for example, aluminum,
titanium, iron or copper, or an alloy including these metals.
[0126] A radio frequency voltage application unit 78 configured to
apply a radio frequency voltage is connected to the supporter
77.
[0127] The radio frequency voltage application unit 78 is
constituted by, for example, a radio frequency power supply
apparatus, a connecting wiring, and so on. Accordingly, the
supporter 77 functions as a lower electrode configured to generate
the plasma P between the upper electrode 18 (see FIG. 1) and the
supporter 77.
[0128] In addition, a ground section 79 is connected to the
supporter 77 so that the supporter 77 has a ground potential with
respect to the direct current voltage. The ground section 79 is
constituted by, for example, a low-pass filter, a grounding wiring,
or the like. Among these, the low-pass filter cuts a radio
frequency voltage applied by the radio frequency voltage
application unit 78, and connects the supporter 77 to the grounding
wiring with respect to only the direct current voltage.
Accordingly, the supporter 77 has a ground potential with respect
to the direct current voltage, and the radio frequency voltage
applied by the radio frequency voltage application unit 78 flows to
the ground section 79 and is not lost.
[0129] In the embodiment having the above-mentioned configuration,
a double-surface electrostatic attractor is constituted by the base
73 formed of a metal, the supporter 77, the direct current voltage
application unit 76 and the ground section 79.
[0130] Actions of the plasma treatment apparatus and the wafer
transfer tray according to the sixth embodiment having the
above-mentioned configuration will be described. In the plasma
treatment apparatus 70 according to the embodiment, as the direct
current voltage is applied to the base 73 formed of a metal by the
direct current voltage application unit 76, the base 73 of the
wafer transfer tray 72 is positively or negatively charged.
Accordingly, the wafer W is electrostatically attracted to the
wafer transfer tray 72 by a Coulomb's force (an electrostatic
attractive force) generated by electric charges induced between the
wafer W placed on the wafer transfer tray 72 and the base 73.
[0131] Meanwhile, the potential of the support body 77 becomes the
ground potential with respect to the direct current voltage by the
ground section 79. Then, as the direct current voltage is applied
to the base 73 by the direct current voltage application unit 76,
the base 73 of the wafer transfer tray 72 is positively or
negatively charged. Accordingly, the supporter 77 is
electrostatically attracted to the wafer transfer tray 72 by a
Coulomb's force (an electrostatic attractive force) generated by
electric charges induced between the support surface 77a of the
supporter 77 and the base 73.
[0132] In this way, the wafer W and the supporter 77 are
electrostatically attracted by the double-surface electrostatic
attractor of the plasma treatment apparatus 70 at both of one
surface 72a and the other surface 72b of the wafer transfer tray
72, respectively. That is, the wafer W is electrostatically
attracted to the one surface 72a of the wafer transfer tray 72 and
the supporter 77 is electrostatically attracted to the other
surface 72b of the wafer transfer tray 72.
[0133] Accordingly, when the plasma P is generated between the
supporter 77 that forms the lower electrode and the upper electrode
18 (see FIG. 1) and plasma treatment is performed on the wafer W,
since the wafer transfer tray can be efficiently and uniformly
cooled, the plasma treatment can be performed on the wafer W
uniformly and accurately.
[0134] In addition, the wafer transfer tray 72 and the supporter 77
closely contact with each other by electrostatically attracting the
supporter 77 to the wafer transfer tray 72. For this reason, the
wafer transfer tray 72 can be efficiently cooled by the cooling gas
supplied from the gas supply unit 25. In addition, loss of the
cooling gas due to dissipation can also be reduced by close contact
between the wafer transfer tray 72 and the supporter 77.
[0135] Then, for example, in comparison with the configuration in
which the wafer transfer tray and the supporter are fixed by the
mechanical clamp as in the related art, since the plasma treatment
apparatus 70 of the present invention electrically attracts the
wafer transfer tray and the supporter, a mechanical movable portion
is reduced. Accordingly, the wafer transfer tray and the supporter
can be easily fixed by a simple configuration.
Seventh Embodiment
[0136] FIG. 8 is a cross-sectional view showing the vicinity of a
support section of a plasma treatment apparatus according to a
seventh embodiment of the present invention. A wafer transfer tray
82 in a support section 81 of a plasma treatment apparatus 80 of
the seventh embodiment has a base 83 formed of a metal, and a first
insulating layer 84a configured to cover an outer circumferential
surface of the base 83.
[0137] The base 83 is formed of a metal such as aluminum, titanium
or iron, or an alloy including these metals. The first insulating
layer 84a is formed of, for example, a ceramic.
[0138] The gas supply unit 25 configured to supply a cooling gas
and serving as a cooling unit configured to cool the wafer transfer
tray 82 is connected to the support section 81. The cooling gas
supplied from the gas supply unit 25 flows to, for example, a gas
flow path (not shown) formed at one surface (a first surface) 82a
side of the wafer transfer tray 82 to cool the wafer transfer tray
82.
[0139] A direct current voltage application unit 86a configured to
apply a direct current voltage is connected to the base 83 formed
of a metal. The direct current voltage application unit 86a is
constituted by, for example, a direct current power supply
apparatus, a connecting wiring, or the like. The base 83 is
positively or negatively charged by application of the
above-mentioned direct current voltage.
[0140] A second insulating layer 84b in which second conductive
layers 85a and 85b for electrostatic attraction are embedded is
formed on a support surface 87a of a supporter 87 configured to
come in contact with the other surface (a second surface) 82b of
the wafer transfer tray 82 to support the wafer transfer tray
82.
The entire second conductive layers 85a and 85b are constituted by
a conductor of a metal or the like, for example, aluminum, tungsten
or titanium, or an alloy including these metals. In addition, the
second insulating layer 84b is formed of, for example, a
ceramic.
[0141] A direct current voltage application unit 86b and a direct
current voltage application unit 86c configured to apply a direct
current voltage are connected to the second conductive layer 85a
and the second conductive layer 85b, respectively. The direct
current voltage application units 86b and 86c are constituted by,
for example, a direct current power supply apparatus, a connecting
wiring, or the like. The second conductive layers 85a and 85b are
charged with polarities that are opposite to each other, and form a
bipolar type electrostatic attractor.
[0142] A radio frequency voltage application unit 88 configured to
apply a radio frequency voltage is connected to the supporter
87.
[0143] The radio frequency voltage application unit 88 is
constituted by, for example, a radio frequency power supply
apparatus, a connecting wiring, or the like. Accordingly, the
supporter 87 functions as a lower electrode configured to generate
the plasma P between the upper electrode 18 (see FIG. 1) and the
supporter 87.
[0144] In the embodiment having the above-mentioned configuration,
a double-surface electrostatic attractor is constituted by the base
83 formed of a metal, the supporter 87, the second insulating layer
84b in which the second conductive layers 85a and 85b are embedded,
and the direct current voltage application units 86a, 86b and
86c.
[0145] Actions of the plasma treatment apparatus and the wafer
transfer tray according to the seventh embodiment having the
above-mentioned configuration will be described. In the plasma
treatment apparatus 80 according to the embodiment, as the direct
current voltage is applied to the base 83 formed of a metal by the
direct current voltage application unit 86a, the base 83 of the
wafer transfer tray 82 is positively or negatively charged.
Accordingly, the wafer W is electrostatically attracted to the
wafer transfer tray 82 by a Coulomb's force (an electrostatic
attractive force) generated by electric charges induced between the
wafer W placed on the wafer transfer tray 82 and the base 83.
[0146] Meanwhile, as the direct current voltages having polarities
that are opposite to each other are applied from the direct current
voltage application units 86b and 86c with respect to the second
conductive layers 85a and 85b embedded in the second insulating
layer 84b formed on the supporter 87, the supporter 87 is
electrostatically attracted to the wafer transfer tray 82.
[0147] In this way, the wafer W and the supporter 87 are
electrostatically attracted by the double-surface electrostatic
attractor of the plasma treatment apparatus 80 at both of the one
surface 82a and the other surface 82b of the wafer transfer tray
82, respectively. That is, the wafer W is electrostatically
attracted to the one surface 82a of the wafer transfer tray 82 and
the supporter 87 is electrostatically attracted to the other
surface 82b of the wafer transfer tray 82.
[0148] Accordingly, when the plasma P is generated between the
supporter 87 that forms the lower electrode and the upper electrode
18 (see FIG. 1) and plasma treatment is performed on the wafer W,
since the wafer transfer tray can be efficiently and uniformly
cooled, the plasma treatment can be performed on the wafer W
uniformly and accurately.
[0149] In addition, the wafer transfer tray 82 and the supporter 87
closely contact with each other by electrostatically attracting the
supporter 87 to the wafer transfer tray 82. For this reason, the
wafer transfer tray 82 can be efficiently cooled by the cooling gas
supplied from the gas supply unit 25. In addition, loss of the
cooling gas due to dissipation can also be reduced by close contact
between the wafer transfer tray 82 and the supporter 87.
[0150] Then, for example, in comparison with the configuration in
which the wafer transfer tray and the supporter are fixed by the
mechanical clamp as in the related art, since the plasma treatment
apparatus 80 according to the embodiment electrically attracts the
wafer transfer tray and the supporter, a mechanical movable portion
is reduced. Accordingly, the wafer transfer tray and the supporter
can be easily fixed by a simple configuration.
DESCRIPTION OF REFERENCE NUMERAL
[0151] 10 Plasma treatment apparatus 12 Supporter 13 Wafer transfer
tray 21 Base 22 First conductive layer 28 Direct current voltage
application unit 28 Ground section
* * * * *